Oil trap for vacuum pumps



May 4, 937. G, W, HARRY 2,079,406

OIL TRAP FOR VACUUM PUMPS Filedsept. 15, 1954 sheets-sheet 1 llmmnWINDSHELD CLEANER .v

' gmc/Wto@ jdaaf? 941622?? G. w. HARRY v 2,079,406

OIL TRAP FOR VACUUM PUMPS Filed Sept. l5, 1934 2 Sheets-Shea?l 2HANIFBLD l wmos Ln cuan W @Ww Fatentee May e? E53? atar .erica 03H..TRAP FR VACUUM IPS Gordon W. Harry, Fiint, Mich., assigner to GeneraiMotors Coii'poration,l Detroit, Mich., a corporation of Delawareappiication september i5, 1934, aerial No. tiene `1i) Claims.

This invention relates to pumps and particularly to a pump operable bythe engine of a motor vehicle to withdraw air from the motor of awindshield cleaner. Pumps of this kind are fred quently of the boostertype, the pump chamber beingin the path of air iiow from. the windshieldcleaner to the engine manifold whereby the manifoldsuction may normallyoperate, unassisted by the vacuum pump, 'to evacuate the windshieldcleaner motor, but in the event of insuiiicient engine suction thenormal operation may be supplemented by the operation of the pump tokeep the windshield cleaner in action. This invention has beenincorporated in a pump of the booster type and is shown associated withsuch a pump having structurally combined therei with a fuel pump. Insuch an installation it is customary to use exible diaphragms and -tooperate these diaphragr'ns by mechanical parts extending into the'enginecrank case. It sometimes happens that hot oil from the crank casereaches the vacuum pump diaphragm and burns it so that more or less oilleaks into the pump chamber. The suction ofthe engine thereupon carriesthe oil to the manifold. This results in high oil consumption, excessivecarbon formation on the cylinder, valves, spark plugs, and cylinder headand interferes with the proper operation of the engine.

It is an object of the present invention to overcome such interferencewith the engine operation and loss of oil by preventing the flow of theoil to the manifold in the event of a leak through the pump diaphragm.

It is a further object of the invention to return the escaping oil tothe engine crank case.

The accompanying drawings illustrate structural' embodiments to attainthe above objects. In the drawings Fig. 1 shows in vertical section acombined pump having my invention incorporated therein.

Fig. 2 is a section on line 2 2 of Fig. 1. Fig. 3 is a perspective ofafloat used in a chamu ber of the vacuum pump.

Fig. 4 is a section on line 4-4 of Fig. 2. Fig. 5 is a section on line5-5 of Fig. 1. Fig. 6 is a section on line 6-6 of Fig. 2. Fig. 'I is aside elevation of another form of the invention. l

Figs. 8 and 9 are sections on lines 8-8 and 9-9 Of Fig. 7.

Referring by reference characters to the drawings, numeral 9 designatesthe crank case of an engine of a motor vehicle. At II is anengineoperated cam actuating in one direction of reciprocation a pushrod i9 guided as shown.

The pump is formed from three castings I5, Il, and i9. Casting I5contains the operating mechanism for the upwardly positioned fuell 5pump and the downwardly located suction pump.A The upper casting I? isclamped to casting i5 together with a diaphragm 2i therebetween. Thediaphragm 4constitutes the movable wall underlying the fuel pump chamber29. Tl'iefuel pump 10 is not a part of this invention and the showing ofthe suspended lter cup'25 and the air dome 2l are intended merely toillustrate well known parts of such a pump. A spring 29 beneath thediaphragm biases the diaphragm toward dls- 15 charge position and a rod3i connected to the diaphragm functions to pull down on the same to makea suction stroke. Within the casting I5 is a pivot pin 33 upon whichrocks a lever 35. The lever is rocked in a clockwise direction by the 20cam li and the rod I3 as will be obvious upon an inspection of thedrawings. The lever is biased for rocking in a counter-clockwisedirection by a 'spring 3l. Also rocking on pin 33 is a link 39 having aninterlocked connection with pump rod 25 3i. The link 39 has a part 4Iadapted to be engaged by the lever 35 as it rocks in its clockwisedirection. Such a rocking produces a suction stroke.

'I'he third casting I9 clamps a diaphragm 43 30 between itself and themiddle casting I5. The casting I9 has a pocket 45 within which a spring4'I is seated. This spring pushes upwardly on diaphragm 43 to enlargethe chamber 49 beneath the diaphragm, this chamber 49 being the cham- 35ber of the suction pump. 'Ihe downward discharge stroke of the pumpdiaphragm is made by a link 5I interlocked with a pump stem 53,rotatable on pin 33 and adapted to be engaged by an arm 55 of lever 35.The bottom of casting 49 I9 is closed by a cover 5l secured by fasteningmeans 59. What may be called a horizontal wall 6I forms the bottom ofthe vacuum pump chamber 49. 'Iwo segmental chambers 63 and 65 are seenbeneath the wall. the segmental chambers 45 being formed by radial wallsin casting I9 as shown by Fig. 5. Chamber is in communication with thewindshield cleaner by a conduit 51. Chamber 63 communicates with theengine manifold by means of a conduit 59. Secured by fas- 50 teningmeans 'Il to the wall 6I is a plate 19. Beneath this plate an opening ismade through wall 6I at 15. 'Ihis opening and an aperture 11 in theplate 'I3 aord communication between the vacuum pump chamber 49 andsegmental cham 5l ber 65. In this passage is secured a valve seat 19.Engaging the seat is a disc valve 8| held in position by a spring 83,the spring being in abutment with an apertured member 85. The springyieldably permits the flow of air from the chamber 65 to the chamber 49.Plate 13 has another opening 81, about which seats a disc valve 89pressed upwardly by a spring 9| seated in a recess 93 of the wall 6I.Through the bottom of this recess is shown an opening communicating withchamber 63. Chamber 63 is formed with a portion circular in crosssection marked 95 within which is a iloat 91 carrying a cone-shapedvalve 99 adapted to seat in the end of the passage |0I communieatingwith a bore |03 extending to the conduit 69.

The lower casting I9 is formed with a horizontal passage |05communicating with chamber 63. Externally this passage is closed by aplug |01. From passage |05 there is an upwardly extended passage |09 thelatter formed of two diameters to form a shoulder. Engaging thisshoulder and closing the'passage is a ball valve III, the valve beingyieldingly held by a spring I I3 acting against a xed abutment II5. Thediaphragm is apertured at IIT to register with the passage |09 and anaperture which is formed in the spring abutment. Above the diaphragm theintermediate casting I5 is formed with a conduit I I9 which, togetherwith conduit |09, constitutes a passage from the region 63 to the regionabove the diaphragm and therefore to the crank case. The ow through thispassage is possible only when pressure in chamber 63 is sufcient toovercome the load impressed on valve I I I. By this means, if a leakoccurs through a damaged diaphragm, not only will the escaping fuelcause the float to rise and close the passage IOI, |03 but the pumpingaction will continue to keep the Windshield cleaner in operation. Afterthe float closes the communication between the manifold and the pump andwindshield cleaner the check valve serves to deliver air drawn from thewindshield cleaner into the pump chamber 49 to thecrank case, and theoil entering the vacuum pump chamber is then also exhausted through thecheck valve back to the crank case. Therefore, the pump cntinues to keepthe windshield cleaner in operation, the discharge of oil to themanifold is checked and loss of oil from the crank case is prevented.

In the embodiment of the invention shown by Figs. 7-9 the oil trap ismade as a separate part and .not as a part of the vacuum pump. Numeral|5| designates the wall of the 'engine crank case. A combined fuel andvacuum pump |53 is secured to the engine casing at |55. It is to beunderstood that this pump is not provided with an oil trap as in thecase of the pump shown by Fig. 1. It has a diaphragm |51 actuated in onedirection as usual by a spring |59. Its outlet valve |6| communicates bymeans of a conduit |63 with an oil trap |65. This trap may be secured tothe engine casing |5| by fastening means |61. lThe trap comprises achamber closed by a cap |69. The conduit |63 communicates with the trapchamber at I1I. The top of the chamber has an outlet |13 connected by aconduit |15 to the engine manifold. It also has an outlet |11registering with an opening |19 extending through the wall |5| into thecrank case. Outlet |11 is controlled by a spring-loaded valve in theform of a ball |8I, its spring |83 engaged by a plug |85 and serving tohold the valve |8| in a position to normally close passage |81communicating with the oil trap chamber proper. Within the chamber is afloat |89 having at its upper end a conical valve |9| closing a bore orpassage |93 leading to outlet |13.

The float is guided by a stem |95 projecting from the cap as shown.

The operation is substantially the same as in -the form first described.When the diaphragm |51 is intact air is drawn into the pump chamberthrough the inlet valve (not shown) and discharged through valve I6I.The air passes through conduit |63 into the trap chamber and out throughpassage |93, outlet |13, and conduit |15 to the engine manifold. In theevent of oil leakage through the diaphragm, oil passes through valve|6I, conduit |63, and collects in the trap chamber |65. The oat thenrises and closes the valve |9I. The-oil and air from the continuouslyoperating pump then lift the spring-loaded valve |8| and the dischargeJoccurs into the crank case through the wall opening |19.

The pump is no longer a booster pump. It performs then the Whole dutyof` exhausting the windshield cleaner motor and delivers the air to theengine crank case instead of to the engine manifold.

I claim:

1. In combination, a vacuum booster pump having a pump chamber, aplurality of conduit means adapted to connect said chamber with anengine manifold anda windshield cleaner, respectively, said pump havinga exible diaphragm, means extending into the engine crank case andadapted to ex said diaphragm, a trap between the pump chamber and themanifold conduit to collect oil escaping through a defective diaphragminto the pump chamber, a valve carrying oat in said trap movable inresponse to collecting oil to close the communication between themanifold and the windshield cleaner and pump, and a check valvecontrolled discharge passage between said pump and crank case wherebythe pump may continue to operate the windshield cleaner unassisted byengine vacuum and whereby escaping oil may be returned to the crankcase.

2. In a suction booster pump for operating the windshield cleaner of amotor vehicle, the combination of a casing member, a movable diaphragmoperable to constitute in cooperation with a part of said casing avariable volume pump chamber, means to reciprocate said diaphragm, saidcasing also formed with an additional postpump chamber, a valve betweensaid variable volume chamber and said additional chamber, a conduitconnected to said variable volume chamber for communication with awindshield cleaner, a conduit connected to said additional chamber forcommunication with the engine manifold, a trapping chamber constitutinga part of said additional chamber, a `valve carrying float in saidtrapping chamber movable to close the conduit to themanifold, avalve-controlled outlet passage from the additional chamber whereby thewindshield cleaner is kept in action by the pump unassisted by themanifold when the float valve closes the communication with themanifold.

3. The invention defined by claim v2, said outlet passage communicatingwith the engine crank case to permit the restoration of oil entering thepump chamber of the booster pump.

4. In combination, a vacuum booster pump the chamber of which is adaptedto be connected to a windshield cleaner and the manifold of the motorvehicle, a trap to collect oil entering ythe chamber of the pump, meanswhereby said collected oil closes the communication with the manifoldand means whereby the pump may discharge air and liquid subsequent tothe closure of said advance communication to the endthat the operationof the windshield cleaner y be continued.

5. In combination, an engine casing, a vacuum pump, an oil trap separatefrom said pump and 5 adapted to trap oil delivered by said pump to saidj trap, said trap having a plurality of discharge outlets, the iirst oneof said outlets being normally open and communicating with the enginemanifold, and the second of said outlets being nor- 10 mally closed andadapted to be opened and provide communication with the engine casingwhen the rst outletv is closed.

6. The invention dened by claim 5 togetherv with a valve carrying oat insaid trap operable l5 under the influence of liquid collecting in saidtrap to close said iirst-named outlet.

7. The invention dei-med by claim 5 together with a valve carrying oatin said ,trap operable under .the iniluence of liquid collecting in said-20 trap to close said rst outlet and a spring-loaded valve controllingthe second outlet.

8. In combination, a vacuum pump having a pump chamber, rst conduitmeans adapted to connect said chamber with a windshield cleaner,

25 said chamber having an outlet valve, second conduit means adapted toconnect the discharge side of said outlet valve to an engine manifold,said second conduit means including a trap, a iioat in said trap movablein response to the collection of liquid therein to close thecommunication through said second conduit means.

9. In combination, a vacuum pump having a pump chamber, iirst conduitmeans adapted to connect said chamber to a windshield cleaner, saidchamber having an outlet valve, second conduit means adapted to connectthe discharge side of said outlet valve with an engine manifold, saidsecond conduit means including a trap, a iioat in said trap, meanscarried by said float and movable therewith in response to thecollection of liquid in said trap to close said second conduit means,third conduit means leading from said trap, a normally closed valveadapted under pressure to open and permit escape of liquid from saidtrap through said third conduit means whereby the windshield cleaner maybe operated by the pump unassisted by manifold suction and wherebyliquid leaking into the pump chamber and trap may be discharged.

10. The invention dened by claim 9, said third A conduit means being incommunication with the engine crank case.

GORDON W. HARRY.

